Turbocharger: Description and Operation

Fig. 1 4-135 turbocharged engine components. 1984-87 Turbo I models:

Fig. 2 4-135 turbocharged engine components. 1984-87 Turbo II models:

GARRET-AIRESEARCH
The turbocharged engines, Figs. 1 and 2, are similar to the standard 4-135 engine. However, many components have been upgraded in order to withstand the more than fifty percent higher power output generated by the addition of the turbocharger, and on Turbo II models, the intercooler. This upgrading includes more durable intake and exhaust valve material, better sealing piston rings, a larger capacity oil pump, select fit bearings and a revised camshaft. Dished piston tops are incorporated to lower the compression ratio to 8:1.

Fig. 3 Section view of Garret-AiResearch T3 type turbocharger:

Fig. 4 Turbocharger water cooling system:

Both turbocharged engines incorporate a Garret-Aireasearch T-3 center housing and wastegate assembly with a Chrysler built compressor and turbine housing and exhaust outlet elbow, Fig. 3. The wastegate is calibrated to regulate maximum boost pressure to a maximum of 9 psi on Turbo I models and 12 psi on Turbo II models.
Wastegate operation is controlled by the wastegate control solenoid. The logic module adjusts maximum boost to different engine operating conditions by varying the duty cycle of the wastegate solenoid.
The turbocharger used on both models incorporate a water cooled turbine end shaft bearing which lowers bearing temperatures, especially after a hot shut-off, to increase the durability of the turbocharger, Fig. 4.
The air to air intercooler, used on Turbo II engines, lowers the incoming fuel charge temperature by about 120° F, allowing the spark to be advanced and the boost pressure increased significantly without causing engine damage through detonation.